A 220 KB PDF named after the 24C02C, with a -1 suffix that likely marks a duplicate or alternate copy. 24C02C is a 2 Kbit (256-byte) I2C serial EEPROM part number, and no device or board is mentioned. Expect pin functions, electrical characteristics and write timing in the document. It is useful for checking connections before reading the chip with a programmer when settings or identification data are suspect. Compare with the other 24C02C file, and back up the chip contents before any write.
The button opens the matching file on RM Schematics, or a source page if it is not catalogued there yet. The original attachment is from @cyberlanelectonik. Enginerys does not host this file.
How to open a .pdf file
The standard format for schematics, block diagrams, power-sequence charts and service manuals.